From: Sami Tolvanen <samitolvanen@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Will Deacon <will@kernel.org>, Jessica Yu <jeyu@kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Peter Zijlstra <peterz@infradead.org>,
Sedat Dilek <sedat.dilek@gmail.com>,
bpf@vger.kernel.org, linux-hardening@vger.kernel.org,
linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH v4 13/17] arm64: use function_nocfi with __pa_symbol
Date: Wed, 31 Mar 2021 14:27:17 -0700 [thread overview]
Message-ID: <20210331212722.2746212-14-samitolvanen@google.com> (raw)
In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com>
With CONFIG_CFI_CLANG, the compiler replaces function address
references with the address of the function's CFI jump table
entry. This means that __pa_symbol(function) returns the physical
address of the jump table entry, which can lead to address space
confusion as the jump table points to the function's virtual
address. Therefore, use the function_nocfi() macro to ensure we are
always taking the address of the actual function instead.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
arch/arm64/include/asm/mmu_context.h | 2 +-
arch/arm64/kernel/acpi_parking_protocol.c | 3 ++-
arch/arm64/kernel/cpu-reset.h | 2 +-
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/psci.c | 3 ++-
arch/arm64/kernel/smp_spin_table.c | 3 ++-
6 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index bd02e99b1a4c..386b96400a57 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -140,7 +140,7 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp)
ttbr1 |= TTBR_CNP_BIT;
}
- replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1);
+ replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1));
cpu_install_idmap();
replace_phys(ttbr1);
diff --git a/arch/arm64/kernel/acpi_parking_protocol.c b/arch/arm64/kernel/acpi_parking_protocol.c
index e7c941d8340d..bfeeb5319abf 100644
--- a/arch/arm64/kernel/acpi_parking_protocol.c
+++ b/arch/arm64/kernel/acpi_parking_protocol.c
@@ -99,7 +99,8 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu)
* that read this address need to convert this address to the
* Boot-Loader's endianness before jumping.
*/
- writeq_relaxed(__pa_symbol(secondary_entry), &mailbox->entry_point);
+ writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)),
+ &mailbox->entry_point);
writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
index ed50e9587ad8..f3adc574f969 100644
--- a/arch/arm64/kernel/cpu-reset.h
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -22,7 +22,7 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry,
unsigned long el2_switch = !is_kernel_in_hyp_mode() &&
is_hyp_mode_available();
- restart = (void *)__pa_symbol(__cpu_soft_restart);
+ restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart));
cpu_install_idmap();
restart(el2_switch, entry, arg0, arg1, arg2);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2a5d9854d664..ac616c59ae92 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1463,7 +1463,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
if (arm64_use_ng_mappings)
return;
- remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
+ remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));
cpu_install_idmap();
remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 62d2bda7adb8..e74bcb57559b 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -38,7 +38,8 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu)
static int cpu_psci_cpu_boot(unsigned int cpu)
{
- int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry));
+ int err = psci_ops.cpu_on(cpu_logical_map(cpu),
+ __pa_symbol(function_nocfi(secondary_entry)));
if (err)
pr_err("failed to boot CPU%d (%d)\n", cpu, err);
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 056772c26098..4c4e36ded4aa 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -88,7 +88,8 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
* boot-loader's endianness before jumping. This is mandated by
* the boot protocol.
*/
- writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr);
+ writeq_relaxed(__pa_symbol(function_nocfi(secondary_holding_pen)),
+ release_addr);
__flush_dcache_area((__force void *)release_addr,
sizeof(*release_addr));
--
2.31.0.291.g576ba9dcdaf-goog
next prev parent reply other threads:[~2021-03-31 21:28 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-31 21:27 [PATCH v4 00/17] Add support for Clang CFI Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 01/17] add " Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 02/17] cfi: add __cficanonical Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 03/17] mm: add generic function_nocfi macro Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 04/17] module: ensure __cfi_check alignment Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 05/17] workqueue: use WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 06/17] kthread: " Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 07/17] kallsyms: strip ThinLTO hashes from static functions Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 08/17] bpf: disable CFI in dispatcher functions Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 09/17] treewide: Change list_sort to use const pointers Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 10/17] lkdtm: use function_nocfi Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 11/17] psci: use function_nocfi for cpu_resume Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 12/17] arm64: implement function_nocfi Sami Tolvanen
2021-03-31 21:27 ` Sami Tolvanen [this message]
2021-03-31 21:27 ` [PATCH v4 14/17] arm64: add __nocfi to functions that jump to a physical address Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 15/17] arm64: add __nocfi to __apply_alternatives Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 16/17] KVM: arm64: Disable CFI for nVHE Sami Tolvanen
2021-03-31 21:27 ` [PATCH v4 17/17] arm64: allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
2021-03-31 21:46 ` [PATCH v4 00/17] Add support for Clang CFI Kees Cook
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